This project will develop a light-adjustable Intraocular Lens that can be post-operatively modified to correct> 2 Diopters of spherical and astigmatic refractive error. The proposed method involves refractive index modulation, and is akin to holography. The proposed approach is to modulate the refractive index of an IOL composed of a cross-linked silicone polymer matrix, a guest macromer, and a photoinitiator. Studies proposed in Phase I are designed to determine the optimal lens composition, and the Aims include the development of a photosensitive acrylate, lens fabrication, irradiation and dose-response curve measurement, and the introduction of selective astigmatism, including correction for hyperopia and myopia. PROPOSED COMMERCIAL APPLICATION: This is a prototype development of a light-adjustable Intraocular Lens, whose power can be precisely adjusted after cataract surgery to correct any residual refractive error. Since more than 50% of cataract surgery patients have refractive errors requiring post-operative correction with spectacles, this Lens will enable these patients to predictably achieve the best possible vision without the need for spectacles.